Tokyo Teen Cohort study: a prospective cohort study on general population of adolescents

Introduction Adolescence is the period when many mental disorders have their peaks of onsets. Investigation into adolescent mental health problems and their risk factors is required, but there has been few prospective cohort studies on adolescent mental health. Objectives This study aimed to prospectively reveal the developmental trajectory of physical and mental health in adolescence, and to investigate factors associated with the trajectory. Methods We launched a prospective cohort study (Tokyo Teen Cohort: TTC) on general population of adolescents at three municipalities in metropolitan area in Tokyo, Japan. Using the resident register, we recruited 10-year-old children from the community between 2012 and 2015. The second, third, and fourth wave of data collection were conducted at 12, 14, 16 years of age, respectively. We collected multidisciplinary data including mental health by self-report questionnaire and home-visit interview. Further, we have launched two subsample studies which focus on biological measures such as brain MRI, EEG, and sex hormones. TTC is based at three research institutes, and ethics approval has been granted by all of the three institutions. Results A total of 3171 children participated the TTC. Of those, 3007 children participated in the second wave of data collection (follow-up rate: 94.8). The third and fourth wave of data collection were completed and more than 80% of children continued to participate in TTC. More than 300 children participated in the two subsample studies. More than 30 papers were already published, and many national/international research collaborations have started. Conclusions The fifth wave of data collection at 20 years of age is being currently conducted. Further national/international collaborations are expected to examine cultural effects on mental health of adolescents. Disclosure of Interest None Declared

Introduction: Adolescence is the period when many mental disorders have their peaks of onsets.Investigation into adolescent mental health problems and their risk factors is required, but there has been few prospective cohort studies on adolescent mental health.
Objectives: This study aimed to prospectively reveal the developmental trajectory of physical and mental health in adolescence, and to investigate factors associated with the trajectory.Methods: We launched a prospective cohort study (Tokyo Teen Cohort: TTC) on general population of adolescents at three municipalities in metropolitan area in Tokyo, Japan.Using the resident register, we recruited 10-year-old children from the community between 2012 and 2015.The second, third, and fourth wave of data collection were conducted at 12, 14, 16 years of age, respectively.We collected multidisciplinary data including mental health by selfreport questionnaire and home-visit interview.Further, we have launched two subsample studies which focus on biological measures such as brain MRI, EEG, and sex hormones.TTC is based at three research institutes, and ethics approval has been granted by all of the three institutions.Results: A total of 3171 children participated the TTC.Of those, 3007 children participated in the second wave of data collection (follow-up rate: 94.8).The third and fourth wave of data collection were completed and more than 80% of children continued to participate in TTC.More than 300 children participated in the two subsample studies.More than 30 papers were already published, and many national/international research collaborations have started.

Conclusions:
The fifth wave of data collection at 20 years of age is being currently conducted.Further national/international collaborations are expected to examine cultural effects on mental health of adolescents.

EPP0703
Mental health and well-being of Children in France : Enabee the 1st nationwide study Introduction: The Covid 19 pandemic has worsened mental health of teenagers and young adults in particular and highlighted the lack of data for children aged 3 -11 years living in France.To fill this gap, Santé publique France, the national public health agency set up the first nationwide study, Enabee, in 2022.Objectives: Enabee (National study on Children wellbeing) aims at monitoring wellbeing and most frequent mental health disorders of children and at understanding associated factors, gathering information from children, parents and teachers.First analyses will be focused on children' and teachers' point of view.Methods: Enabee is a nationwide cross sectional study.Elementary and nursery schools were randomly selected in Metropolitan France.Then a maximum of four classes were randomly selected in each school.Elementary school children (from 6 to 11 years old) gave their own assessment of wellbeing and mental health using the following self-administrated questionnaires on tablets: the Kindl and the Dominique Interactive.To get a comprehensive evaluation, parents and teachers also filled the web-administrated Strengths and Difficulties Questionnaire for each child.The parents' questionnaire also included questions on child's life habits and global health, parenting attitudes, parent's mental health, covid 19, major life events and household social situation.A pilot study was launched in January to assess the feasibility and the acceptance before implementing the study at a nationwide level.Key stakeholders of education, family and health participated at the setting up of the study.Results: 706 schools were selected and 399 participated (participation rate 57%).Data were collected from May 2 nd to July 31 st 2022.

Table 1
All-cause and cause-specific mortality of people hospitalised for depression inScotland 2000-19